Cat tree tower



FIG. 1 is a front perspective view of a cat tree tower showing my new design;

FIG. 2 is rear perspective view thereof;

FIG. 3 is a left-side perspective view thereof;

FIG. 4 is a right-side perspective view thereof;

FIG. 5 is a top perspective view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines in the drawings illustrate the portions of cat tree tower which form no part of the claimed design. 

CLAIM The ornamental design for cat tree tower, substantially as shown and described. 